In laying pipe such as in a gas or oil pipe line it is conventional that lengths of the pipe are supported end to end on stack lumber pieces known as “skids” so that the pipe lengths can be held at a required height to be supported and aligned end to end for welding of the lengths prior to feeding of the completed welded length into a trench adjacent to the stacks.
Thus the pipe lengths are initially arranged end to end and are properly aligned by arranging sufficient of the lumber pieces to support the pipe length at the required height. With the pipe lengths so supported, the welding is carried out to form the lengths into a continuous length for laying in the ground.
The pipe is then lifted from the supporting stacks and deposited in a continuous action along its length into the ground by a train of tracked vehicles at spaced positions along the length, each carrying suitable operation elements so that the continuous pipe length can be fed from the supported position into the trench. At some point during laying or after the pipe has been laid, it has been necessary to remove the lumber pieces from the stacks and to collect the lumber pieces into a transport container for removal from the site and preferably for re-use at a further location along the pipeline.
A the present time the lumber pieces which are conventionally either four or five feet in length and 6 inches by 4 inches in cross section are lifted manually and handled manually for stacking onto a transport container. This manual process is expensive and time consuming since it requires a gang of laborers working hard and commanding relatively high wage rates. In many cases that stack has been disturbed so that the pieces are strewn and in some cases the pieces are compressed into the ground by the tracks of the passing vehicles.
While this step relatively minor one in the process of laying the pipe line, it constitutes a significant expense and therefore provides a significant opportunity for manufacturer of an effective machine which will carry out this step while eliminating or reducing the manual labor involved.
In U.S. Pat. No. 5,934,861 issued Aug. 10th 1999 to one of the present inventors, which corresponds to Canadian Application 2,241,682 published 26th Feb. 1999, a first proposal was made for a machine which picks up the pieces and conveys them to a transport truck to one side of the machine. While this proposal included a number of basic principles which are used herein and which form the basis of this invention, yet further improvements have been made herein to provide a machine with improved operation and ergonomics